deer-flow/backend/tests/test_read_file_tool_binary.py

"""read_file tool behaviour on binary files.

``read_file`` decodes with UTF-8. Binary uploads (``.xlsx``, images, ...) raise
``UnicodeDecodeError`` deep in the sandbox layer, which previously surfaced to
the model as a vague ``Unexpected error reading file`` message. The model could
not tell that the file was binary, so it retried ``read_file`` instead of
switching to ``bash`` + pandas/openpyxl — burning LLM round-trips. These tests
pin the actionable error contract and guard the normal text path.
"""

from pathlib import Path
from types import SimpleNamespace

from deerflow.sandbox.local.local_sandbox import LocalSandbox
from deerflow.sandbox.tools import read_file_tool


def _local_runtime(tmp_path: Path) -> SimpleNamespace:
    for sub in ("workspace", "uploads", "outputs"):
        (tmp_path / sub).mkdir(parents=True, exist_ok=True)
    thread_data = {
        "workspace_path": str(tmp_path / "workspace"),
        "uploads_path": str(tmp_path / "uploads"),
        "outputs_path": str(tmp_path / "outputs"),
    }
    return SimpleNamespace(
        state={"sandbox": {"sandbox_id": "local:t1"}, "thread_data": thread_data},
        context={"thread_id": "t1"},
    )


def test_read_file_tool_binary_file_returns_actionable_hint(tmp_path, monkeypatch) -> None:
    runtime = _local_runtime(tmp_path)
    # .xlsx is a zip container: header bytes PK\x03\x04 plus a non-UTF-8 byte 0x82
    # that makes strict UTF-8 decoding fail (the exact byte seen in the field logs).
    (tmp_path / "uploads" / "data.xlsx").write_bytes(b"PK\x03\x04\x14\x00\x00\x00\x08\x00\x82\x6a\xb1\x55")
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_sandbox_initialized", lambda runtime: LocalSandbox("t1"))
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_thread_directories_exist", lambda runtime: None)

    result = read_file_tool.func(
        runtime=runtime,
        description="read uploaded excel",
        path="/mnt/user-data/uploads/data.xlsx",
    )

    assert "Unexpected error" not in result, result
    assert "binary" in result.lower(), result
    # The model must be steered to bash + pandas/openpyxl, not another read_file.
    assert "bash" in result.lower(), result


def test_read_file_tool_text_file_unaffected(tmp_path, monkeypatch) -> None:
    runtime = _local_runtime(tmp_path)
    (tmp_path / "uploads" / "notes.txt").write_text("hello 你好\nsecond line", encoding="utf-8")
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_sandbox_initialized", lambda runtime: LocalSandbox("t1"))
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_thread_directories_exist", lambda runtime: None)

    result = read_file_tool.func(
        runtime=runtime,
        description="read notes",
        path="/mnt/user-data/uploads/notes.txt",
    )

    assert "hello 你好" in result, result
    assert "binary" not in result.lower(), result


def test_read_file_tool_passes_line_range_into_sandbox(monkeypatch) -> None:
    captured: dict[str, int | str | None] = {}

    class RangeAwareSandbox:
        def read_file(
            self,
            path: str,
            start_line: int | None = None,
            end_line: int | None = None,
        ) -> str:
            captured["path"] = path
            captured["start_line"] = start_line
            captured["end_line"] = end_line
            return "line 1\nline 2"

    runtime = SimpleNamespace(state={"sandbox": {"sandbox_id": "aio:test"}}, context={"thread_id": "t1"})
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_sandbox_initialized", lambda runtime: RangeAwareSandbox())
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_thread_directories_exist", lambda runtime: None)

    result = read_file_tool.func(
        runtime=runtime,
        description="read top of file",
        path="/mnt/user-data/workspace/huge.log",
        start_line=1,
        end_line=10,
    )

    assert result == "line 1\nline 2"
    assert captured == {
        "path": "/mnt/user-data/workspace/huge.log",
        "start_line": 1,
        "end_line": 10,
    }


def test_read_file_tool_passes_open_ended_ranges_into_sandbox(monkeypatch) -> None:
    calls: list[tuple[int | None, int | None]] = []

    class RangeAwareSandbox:
        def read_file(self, path: str, start_line: int | None = None, end_line: int | None = None) -> str:
            calls.append((start_line, end_line))
            return "line 1\nline 2"

    runtime = SimpleNamespace(state={"sandbox": {"sandbox_id": "aio:test"}}, context={"thread_id": "t1"})
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_sandbox_initialized", lambda runtime: RangeAwareSandbox())
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_thread_directories_exist", lambda runtime: None)

    start_only = read_file_tool.func(
        runtime=runtime,
        description="read tail",
        path="/mnt/user-data/workspace/huge.log",
        start_line=1,
    )
    end_only = read_file_tool.func(
        runtime=runtime,
        description="read head",
        path="/mnt/user-data/workspace/huge.log",
        end_line=10,
    )

    assert start_only == "line 1\nline 2"
    assert end_only == "line 1\nline 2"
    assert calls == [(1, None), (None, 10)]


def test_read_file_tool_validates_range_order(monkeypatch) -> None:
    runtime = SimpleNamespace(state={"sandbox": {"sandbox_id": "aio:test"}}, context={"thread_id": "t1"})
    monkeypatch.setattr("deerflow.sandbox.tools.ensure_sandbox_initialized", lambda runtime: object())

    result = read_file_tool.func(
        runtime=runtime,
        description="bad order",
        path="/mnt/user-data/workspace/huge.log",
        start_line=20,
        end_line=10,
    )

    assert "start_line > end_line" in result